Method for discharging ir and radar countermeasure means and/or laser reflectors from a dispenser intended for the purpose, and dispenser intended for discharging such countermeasure

ABSTRACT

The invention relates to a method and an arrangement for discharging countermeasure means from a carrier craft in the form of an aircraft or equivalent. In this connection, the countermeasure means is intended to be spread initially in the form of unit packs ( 13, 13′  and  20 ) which, after they have left the carrier craft, are to screen the same ( 23 ) from missiles ( 24 ) approaching is guided by built-in sensors, or other threats. It is especially characteristic of the invention that the unit countermeasure packs ( 13, 13′  and  20 ) are spread from the carrier ( 2 ) transversely to the lying direction of the carrier craft.

[0001] The present invention relates to a method for dischargingcountermeasure means, such as radar chaff or hot IR chaff, laserreflectors or equivalent from an electromechanical dispenserarrangement. The invention also relates to a dispenser arrangementdesigned in accordance therewith.

[0002] The most serious threat to modern fighter aircraft and transportaircraft is the self-guiding missile equipped with radar, IR or lasersensors, which can be fired either from enemy aircraft or from theground. In order to protect own aircraft, these are therefore nownormally provided with equipment so as to be capable, when they areattacked or fear attack, of dispensing various types of countermeasuremeans. An example of such equipment is the BOL dispenser produced andpatented by ourselves. In this connection, reference may be made to ourU.S. Pat. Nos. 4,417,709 and 4,650,092. By means of this type ofdispenser, the dispensing of countermeasure means can be simplycontrolled and adapted to the threat situation existing at the time. Avery common form of our dispenser, which is of electromechanical type,is the kind which is built into the load-bearing beam of the aircraftand can therefore serve as a mounting for other load at the same time.This type of countermeasure dispenser, which has become widely usedwithin a large number of different air forces, nevertheless has thedisadvantage that the quantity of countermeasure means it can contain islimited by the normal outer dimensions of the load-bearing beam. Giventhat the various sensors of the missiles are becoming increasinglysophisticated, however, demands are becoming more exacting with regardto the quantity of countermeasure means necessary for each protectiveaction and the rapidity with which the countermeasure means have to bespread in order for it to be possible for the sensors of an attackingmissile to be deceived and the own aircraft to manage to move out of theway. At the same time, access to various missile weapons has increasedmarkedly, as a result of which the need for it to be possible to performmore or longer protective actions within one and the same mission hasincreased to a corresponding extent.

[0003] The present invention therefore relates to an improveddischarging method and an improved type of spreader for countermeasuremeans adapted for a greater quantity of countermeasure means carried,which thus makes possible more or longer countermeasure actions oneafter another. The countermeasure types principally concerned in thisconnection are conventional radar chaff made chiefly from aluminizedfoil or fibres, hot IR chaff, and also laser-reflecting fibres or foils.

[0004] With the present invention, a cloud or a screen of protectivemeans is therefore produced around the carrier aircraft by means of amethod which involves unit-packed countermeasure means being spreadsuccessively but in one and the same operation from a number ofmagazines arranged parallel to one another, spreading taking place in alaterally directed manner transversely to the flying direction of theaircraft serving as the carrier. In this connection, each magazine isgiven its own discharging direction which preferably extends radiallyoutwards from a common main axis, the discharging directions also beinguniformly distributed all the way around. As the unit packs are designedin such a manner that, as soon as they have left the spreader, they willbe broken up by the relative wind and thus in turn spread theircontents, a protective cloud is thus produced rapidly, which concealsthe carrier aircraft and confuses missiles aimed at it.

[0005] Inside each magazine included in the arrangement according to theinvention, a simple feed spring, for example, can serve for feeding theunit countermeasure packs to a discharging location specific to themagazine in question. Provided that the discharging locations of all themagazines are arranged in one and the same transverse plane arrangedtransversely to the flying direction of the aircraft, one and the samerotating discharger or ejector can be used for successively, as itpasses the magazines, ejecting the countermeasure pack next in orderlocated there. If it is desirable to use this variant, the variousmagazines should therefore be arranged parallel to one another around acentre axis, the centre axis also constituting a bearing point for therotating discharger which can itself be in the form of a cam which,during its rotation past a countermeasure pack present in eachdischarging location, moves the pack in the discharging direction untilit has completely left the discharging location. In order to bring aboutthe desired radial discharge, the various countermeasure packs shouldalso be guided up in the desired discharging direction until the momentwhen these have completely left the spreader. In this connection, thevarious countermeasure packs are preferably arranged stacked on top ofone another in the magazines, with their respective greatest extentslying in the lateral direction transversely to the feed direction of thedispenser. The spreading of the countermeasure packs is thus carried outin the longitudinal direction of the packs, that is to say transverselyto the feed direction of the magazines.

[0006] The spreader arrangement described above in terms of its basicprinciples therefore comprises a number of magazines arranged parallelto one another around a central axis, and an ejector arranged rotatablyabout this axis. It should be possible for the whole of thisarrangement, without major problems, to be built into one of the rocketcapsules intended for originally unguided attack rockets, which areavailable in great numbers for most combat and transport aircraft inservice today. This could be a good use for at least some surplus rocketcapsules, of which there must be many because, in the current situationwith existing anti-aircraft missiles, it is only entirely unprotectedtargets which are likely to be attacked using unguided attack rockets.If rebuilding such a rocket capsule for this purpose is anticipated, itmay be necessary to manufacture a new nose cone for the capsule becausethe nose cone, in the original state, is often discarded before therockets are fired, but, when used as a countermeasure dispenser, thenose cone needs only to be provided with discharger openings adapted tothe intended dispensing directions, if the dispensing of countermeasuremeans takes place in the front part of the dispenser.

[0007] A further improvement of the spreading of countermeasure meanscan also be brought about by arranging angled swirl plates in closeproximity to the discharging openings through which the countermeasurepacks leave the spreader. By means of such swirl plates, a turbulent airflow is brought about just around the discharging opening of thespreader, and the spreading of the countermeasure means itself is thusimproved as soon as it has left its unit pack. Especially in the case ofrapid combat aircraft, it will probably also be suitable to arrange somesort of wind deflector in the flying direction of the plane in front ofeach discharging opening, because the unit packs could otherwise, inspite of high discharging speed, be broken by the relative wind evenbefore they have completely left their discharging opening. In thisconnection, these wind deflectors can be in the form of a belliedprojection, a guide rail in the form of an angled plate or equivalent.

[0008] As already indicated, the dispenser arrangement according to theinvention can be contained in a carrier with in principle the same outerconfiguration as conventional rocket launchers or consisting of arebuilt rocket launcher of such a type, of which there have long beengreat quantities intended for all combat and transport aircraft inservice. The carrier is therefore in the form of an oblong cylindricalcapsule, and this shape provides room for a number of magazines arrangedside by side extending in the longitudinal direction of the capsule andalso a drive arrangement, arranged centrally in the middle of thecapsule, for a rotating discharger which, when it is activated, duringits rotation successively ejects one after another the unitcountermeasure packs which lie next in order in the discharginglocations of the magazines. The actual discharging of the unitcountermeasure packs, which according to the invention is to take placeradially in relation to the longitudinal axis of the carrier capsule,can of course be arranged in either the front or the rear end of thecarrier capsule and/or somewhere in between.

[0009] In an especially preferred arrangement, magazines of standardcountermeasure packs are therefore arranged around a central space, inwhich the drive arrangement for the rotating discharger is arranged,and, at the same time, each of the magazines is provided with its owndischarging location, and all these discharging locations are positionedin a common plane which is arranged transversely to the dischargingdirection of the magazines and in which the discharger also rotates whenit is activated. With this setup, a single discharger can thereforeserve all the magazines by, during its rotation, successively passingthe discharging locations of the various magazines. Each magazine thenhas its own guide path for controlling the general ejection of thecountermeasure packs, while the feed of the unit packs within eachmagazine can be effected by means of separate feed springs or by acommon ball screw which, by means of separate feed arms, effects thefeed of the countermeasure packs within all the magazines.

[0010] The packs can contain previously known types of interferencematerial and reflective material as mentioned above, and, when thesepacks have left the spreader, they open and form material clouds capableof diverting the threat concerned.

[0011] The invention is not limited to the embodiments shown above byway of example but can undergo modifications within the scope of thepatent claims below.

[0012] The invention will be described in greater detail below by meansof illustrative embodiments with reference to accompanying drawings, inwhich:

[0013]FIG. 1 shows a spreader for countermeasure means with a partlycut-away nose cone,

[0014]FIG. 2 shows on larger scale a cross section along the line II-IIin FIG. 1,

[0015]FIG. 3 shows the section III-III in FIG. 2,

[0016]FIG. 4 shows a special type of wind deflector at the dischargingopenings as protection during discharging, and swirl plates forimproving the spreading of the countermeasure means,

[0017]FIG. 5 shows a unit countermeasure pack, and

[0018]FIG. 6 shows in a general manner the use of the arrangementaccording to the invention.

[0019] The spreader 1 for countermeasure means shown in FIG. 1 has acircular cylindrical main body 2 with mounting and connecting eyes 3 andalso a partly cut-away front nose cone 4, inside which it is possible toobserve the discharging locations 5-10 for six different magazines whichare arranged in the longitudinal direction of the body and have beengiven the references 5 a-10 a although only 6 a and 9 a are actuallyvisible in FIG. 3. FIGS. 1, 2 and 3 also show a discharger 12 which canrotate about a central axis 11 and, when it rotates past the discharginglocation of each magazine in the direction of the arrow a, accelerates aunit countermeasure pack 13 present there in the radial direction to asufficient speed for the latter to leave the countermeasure spreader viaa discharging opening 5′-10′ corresponding to the magazine concerned.The discharging direction of the unit pack 13 is indicated by the arrowb in FIG. 2.

[0020] For further details, reference is also made to FIG. 2 and FIG. 3in addition to FIG. 1, corresponding components having the samereferences irrespective of the different scale of the figures. Therotating discharger 12 therefore has a curved front edge 12′ which,during its rotation, is brought into contact with the curved inner edge,here 13″, of the unit countermeasure pack 13′. By virtue of the frontedge 12′ of the discharger being designed in such a manner that itscontact with the curved end edge 27′ (see FIG. 5) of the unit pack isprogressively displaced from its outer edge towards its centre duringcontinuous lengthening of the lever formed by the discharger from itscentre of rotation to the edge of the pack, the unit pack will be movedin the discharging direction until it completely leaves the spreader.

[0021] As can be seen from FIG. 2 and, to a lesser extent, from FIG. 3,guide edges 5″-10″ and 5′″-10′″ are arranged along the dischargingdirections originating from each magazine. Furthermore, the direction ofrotation of the discharger 12 is designated by a, and the dischargingdirection of the countermeasure pack 13 and 13′ by b.

[0022] In FIG. 3, the drive motor 14 of the discharger 12 is also shown.

[0023] As far as FIG. 4 is concerned, this figure shows a variant inwhich the discharging opening of each magazine is arranged along acylindrical part of the carrier body 15. Also shown are four dischargingopenings 16-19 for spreading countermeasure means, a unit countermeasurepack 20 on the way out of the opening 18, and two swirl plates 21arranged close to the discharging openings for the purpose of increasingthe turbulence in the air next to the discharging openings in order inthis way to speed up the spreading of the countermeasure means. Thereare also wind deflectors in the form of projections 22 arranged on thewind side or the side facing the air flow at each of the dischargingopenings 16-19. The purpose of these wind deflectors is to prevent theinherently very delicate unit packs being broken before they have hadtime completely to leave the spreader. In the figures, these winddeflectors have been shown as streamlined projections but they canactually have any shape.

[0024]FIG. 5 shows a unit pack 13 of any type of countermeasure means.It consists of an outer frame 27 with curved end edges 27′ surrounding acentral portion 28 containing countermeasure material, preferably in theform of fine fibres or pieces of foil packed transversely to the mainplane of the pack. The intention is that the countermeasure materialshould leave the frame as soon as the pack has left the spreader.

[0025] Finally, FIG. 6 gives a small-scale indication of how theinvention is used, even though this is per se previously known art.Accordingly, the aircraft 23 has had a radar-guided missile 24 fired atit and has in this connection spread the countermeasure cloud 25 at thesame time as the pilot of the aircraft 23 prepares and performs anevasive manoeuvre 26. In this connection, the intention is that themissile 24 will then go towards the decoy formed by the countermeasurecloud 25.

1. A method for, from a secondary carrier, in the form of a load capsuleor equivalent, arranged on a carrier craft, in the form of an aircraftor equivalent, spreading a countermeasure means arranged initially inunit packs and intended, after the contents of the unit packs have leftthe latter outside the secondary carrier, to screen the carrier craft orform a decoy in order to deceive or confuse a threat aimed at thecarrier craft, wherein the unit countermeasure packs are spreadmechanically from the carrier from a number of magazines via discharginglocations specific to each of the magazines, in which locations the unitpacks are given a defined spreading direction transverse to the flyingdirection of the carrier craft.
 2. The method according to claim 1,wherein the unit packs from the various discharging locations aresuccessively spread radially with regard to a common axis, the spreadingdirections of all the magazines being arranged in such a manner thattogether they cover at least most of the way around the carrier.
 3. Themethod according to claim 1, wherein at least two of the discharginglocations for the magazines included in the carrier are arranged in oneand the same plane transverse to the main flying direction of thecarrier and are served by one and the same rotating spreader elementwhich is made successively to pass the discharging locations of themagazines and in this connection give the unit packs next in order ineach of the magazines the speed necessary for discharge.
 4. Anarrangement for, from a secondary carrier, in the form of a load capsuleor equivalent, arranged on a carrier craft, in the form of an aircraftor equivalent, spreading a countermeasure means arranged initially inunit packs and intended, after the contents of the unit packs have leftthe packs outside the secondary carrier, to screen the carrier craft orform a decoy in order to deceive or confuse a threat aimed at thecarrier craft, wherein it comprises a number of magazines arranged sideby side for feeding unit countermeasure packs to a discharging locationdefined for each magazine, the discharging locations of a number ofmagazines included in the carrier being arranged in one and the sameplane which, with the carrier interconnected with the carrier craft,lies transversely to the main flying direction of the carrier craft andwithin which plane each magazine has been designed with its own radialdischarging direction.
 5. The arrangement according to claim 4, whereinthe discharging directions of the magazines are arranged in such amanner that all the discharging directions together cover most of theway around.
 6. The arrangement according to claim 4, wherein all themagazines included in the carrier are arranged around a central axiswhich also constitutes a bearing for a rotating discharger which, whenit is activated, successively passes the discharging location of each ofthe magazines and there gives the unit packs next in order the necessarydischarging speed in the relevant discharging direction for the magazineconcerned.
 7. The arrangement according to claim 6, wherein the rotatingdischarger is in the form of a single-bladed or multi-bladed planepropeller with a front edge which is curved in its direction of rotationand which, during its rotation past the discharging location of each ofthe magazines, strikes the respective unit packs with a lever, which iscontinuously increasingly long at least during part of the discharge,and thus progressively moves the unit pack in the discharging directionuntil the unit pack has left the discharging location.
 8. Thearrangement according to claim 6, wherein unit packs included thereinhave a curved contact surface facing the rotating discharger.
 9. Thearrangement according to claim 6, wherein the magazines and thedischarger are arranged in such a manner in the carrier that thedischarge takes place in at least one place along the long side of thecarrier, the magazines being arranged in its longitudinal direction andthe feed of new unit packs in the magazines to the discharging locationof each of the magazines consequently taking place in or towards theflying direction of the carrier craft.
 10. The arrangement according toclaim 4, further comprising wind deflectors are arranged on the windside of each of the discharging openings in order to prevent thecountermeasure packs being broken before they have had time completelyto leave the discharging openings.
 11. The arrangement according toclaim 4, further comprising angled swirl plates arranged on the outsideof the carrier close to the discharging openings for the unitcountermeasure packs in order to facilitate the spreading ofcountermeasure means.